Hi there,
We already added this as a feature request.Please kindly consider that the way the builder is coded is too much complicated to have a support for touch devices. The whole builder is meant to be used by devices having the mouse and the traditional way of the development.
I am sure that the need for support of the touch devices will need a complete overhaul of the base code of the builder which is not feasible at the moment for the percentage of customers using the touch devices for development such as iPad Pro.
I just wanted to set the expectations here, but for sure we added the Feature Request already and if the requests get enough votes our development team will surely consider implementing the feature.
Thank you all for your understanding and making your voice heard.